74 NEW itnionip.t; of the 



means so hrilliant in the nacre, nor is it so dark in the epidermis. It is also near to 

 fallax (nobis). On the side there is a disposition to yellowness, which exhibits the 

 greenish rays. 



Unio othcaloogensis. pi. 14, fig. 54. 



Testa Ia3vi, subtriangulari, vcntricosa, subaequilaterali; valvulis crassis, antic6 crassioribus ; natibus subgran- 

 dibus, ad apices undulatis ; epidermide lutescente, perlsevi, nitida, eradiata ; dentibus cardinalibus 

 crassis, obliquis, crenulatis et in utroquo valvulvo duplicibus ; lateralibus brevibus subrectisque ; mar- 

 garita alba, et iride.scente. 



Shell smooth, subtriangular, ventricose, subequilateral ; valves thick, thicker be- 

 fore ; beaks rather large, undulate at the tip ; epidermis yellowish, very smooth and 

 bright, without rays ; cardinal teeth thick, oblique, crenulate and double in both 

 valves ; lateral teeth short and nearly straight, nacre white and iridescent. 

 Proc. Acad. Nat. Soi. 1857, p. 32. 



Ilah. — Othcalooga Creek, Gordon County, Georgia. Bishop Elliott. 



My cabinet and cabinet of Bishop Elliott. 

 Diam. "6, Length "7, Breadth "8 inches. 



Shell smooth, subtriangular, ventricose, nearly equilateral, obtuse behind and round 

 before ; substance of the shell thick, much thicker before ; beaks rather large, mi- 

 nutely undulate at the tip ; ligament very short and thin ; epidermis yellowish in- 

 clined to orange, very smooth, highly polished, bright, without rays, and with a 

 single line of growth near to the middle ; umbonial slope very much rounded ; cardi- 

 nal teeth very large, oblique, very much crenulated and double in both valves ; lat- 

 eral teeth short, lamellar, rather thick and nearly straight ; anterior cicatrices confluent 

 and very deeply impressed, posterior cicatrices confluent; dorsal cicatrices small, 

 placed nearly in the center of the cavity of the beak, under the cardinal tooth ; 

 cavity of the shell deep and rounded ; cavity of the beaks shallow and subangular ; 

 nacre white and iridescent. 



Soft Parts. — Branchial uterus situated on nearly two-thirds of the outer branchite, 

 the branchial ovisacks being very full and comparatively large for so diminutive a 

 species, and number about twelve on each side ; the color whitish. BrancMa; very 

 small, rounded below, the inner one a little the larger, united the whole length of 

 abdominal sack. Palpi small, thin, transversely elongate, suboval, united a short dis- 

 tance on the posterior edges. Mantle thin, thickened at the palleal border and co- 

 lored at the edge, crenulate below the branchial opening where it is also deeply co- 

 lored and has a callus on each side. Branchial opening very small, with minute 

 brownish papilljB on the inner edges. Anal opening very small, with very minute 

 papillae on the inner edges. Super-anal opening proportionately large, not colored on 

 the edge, united for a short distance below. Color of the mass whitish. 



Emhryonic shell clear white, subrotund, and very near to perptlerns (nobis) in out. 

 line. 



